The present invention relates to compositions of matter which are adapted for use as vitreous fertilizers.
The use of vitreous fertilizers has been well known for over thirty years. A paper appeared in Chemical and Metallurgical Engineering April 1945 by Badger and Bray entitled "Soluble glass may offer fertilizer possibilities".
The opening paragraph of this paper reads as follows: "It is a curious coincidence that, with the exception of water, organic matter, and nitrogen, all of the elements required for plant growth may be incorporated in a glass. The major chemical elements, as potassium, calcium, magnesium, and phosphorus, as well as the minor elements needed by plants--as sulphur, iron, boron, zinc, manganese, and copper--may be included in the glass structure. This fact, coupled with the knowledge that glasses may be made with varying resistances to solution by water, suggests a method whereby plant nutrients may be made available to the plant without danger of "burning" it, by a choice of a suitable glass composition which has the desired rate of disintegration. The ease with which glass can be manipulated suggests many commercial adaptations for soil-less growth experiments as well as ordinary applications for soil enrichment. For example, nutrient glass may be pressed into various shapes, as flower pots or blocks of various sizes; surfaces with large areas exposed to the soil may be formed readily by grinding the glass into powder or by blowing it into glass wool."
The benefits of using vitreous fertilizers which dissolve at a relatively high rate as compared with conventional glasses but at a low rate as compared with conventional fertilizers are manifold.
Because of the slow dissolution rate, an adequate level of nutrient can be maintained at the level of the plant roots during the whole period of plant growth without applying an excessive amount of fertilizer and without the necessity for frequent fertilizer spreading.
If excessive amounts of conventional chemical fertilizer are applied, firstly there is severe danger of burning or searing the plants, and secondly, large proportions of the fertilizer will be dissolved by rainfall or other watering and carried down into the water table or to a nearby watercourse. This is wasteful.
Frequent application of smaller quantities of conventional chemical fertilizers is expensive in time and equipment, and the frequent passage of heavy spreading equipment has been known to cause excessive break-up of the soil which reduces growth yield.
Vitreous fertilizers may be applied one every two to four years with very good results, and they are also cleaner and easier to handle than conventional chemical fertilizers.